Multi-temperature transport refrigeration system

ABSTRACT

A multi-temperature transport refrigeration system (TRS) for a refrigerated transport unit having an interior space divided into a plurality of zones is disclosed. The multi-temperature TRS includes a thermal accumulator in a first of the plurality of zones. The thermal accumulator includes a phase change material in a first state to absorb thermal energy from the first of the plurality of zones of the interior space during transformation to a second state. The first of the plurality of zones is maintained at a first temperature and a second of the plurality of zones is maintained at a second temperature.

FIELD

Embodiments of this disclosure relate generally to a transport refrigeration system (TRS). More specifically, the embodiments relate to a multi-temperature TRS including a thermal accumulator having a phase change material (PCM).

BACKGROUND

A transport refrigeration system (TRS) is generally used to control an environmental condition such as, but not limited to, temperature, humidity, air quality, or the like, of a refrigerated container. Examples of refrigerated containers include, but are not limited to, a container on a flat car, an intermodal container, a truck, a boxcar, or other similar transport unit (generally referred to as a “refrigerated transport unit”). A refrigerated transport unit is commonly used to transport perishable items such as, but not limited to, produce, frozen foods, and meat products. Generally, a transport refrigeration unit (TRU) is attached to the refrigerated transport unit to control the environmental condition of a cargo space. The TRU can include, without limitation, a compressor, a condenser, an expansion valve, an evaporator, and fans or blowers to control the heat exchange between the air inside the cargo space and the ambient air outside of the refrigerated transport unit.

SUMMARY

Embodiments of this disclosure relate generally to a transport refrigeration system (TRS). More specifically, the embodiments relate to a multi-temperature TRS including a thermal accumulator having a phase change material (PCM).

A suitable thermal accumulator or thermal accumulator module is described in U.S. Provisional patent application Ser. No. 14/268,239 (Attorney Docket 20420.0140US01), filed on May 2, 2014, and titled “Thermal Accumulator for a Transport Refrigeration System,” which is incorporated herein by reference in its entirety.

In some embodiments, an interior space of a refrigerated transport unit can be divided into a plurality of zones. A first of the plurality of zones can be maintained at a first set point temperature and a second of the plurality of zones can be maintained at a second set point temperature. In some embodiments, the first and second set point temperatures can be the same. In other embodiments, the first and second set point temperatures can be different.

The first of the plurality of zones can be heated or cooled using one or more thermal accumulators. In some embodiments, the second of the plurality of zones can be heated or cooled with a fan that pulls air from the first of the plurality of zones into the second of the plurality of zones. In some embodiments, the TRS can include a transport refrigeration unit (TRU) with an evaporator and/or connected to one or more remote evaporator units. In such embodiments, the first and the second of the plurality of zones can be cooled by the TRU via the evaporator and/or the one or more remote evaporator units. In some embodiments, the second of the plurality of zones can be cooled using one or more thermal accumulators. It is appreciated that any of the above embodiments can be combined with one another.

In some embodiments, the refrigerated transport unit can include a transport refrigeration unit (TRU). In other embodiments, the TRU need not be present. Removing the TRU can, for example, reduce the weight of the refrigerated transport unit, thereby increasing its fuel efficiency. In some embodiments, removing the TRU can also reduce noise.

A multi-temperature transport refrigeration system (TRS) for a refrigerated transport unit having an interior space divided into a plurality of zones is disclosed. The multi-temperature TRS includes a thermal accumulator in a first of the plurality of zones. The thermal accumulator includes a phase change material in a first state to absorb thermal energy from the first of the plurality of zones of the interior space during transformation to a second state. The first of the plurality of zones is maintained at a first temperature and a second of the plurality of zones is maintained at a second temperature.

A refrigerated transport unit is disclosed. The refrigerated transport unit includes an interior space and a partition dividing the interior space into first and second zones. The first zone can be maintained at a first set point temperature and the second zone can be maintained at a second set point temperature. The refrigerated transport unit includes a transport refrigeration system. The transport refrigeration system includes a thermal accumulator in the first zone. The thermal accumulator includes a phase change material in a first state to absorb thermal energy from the first zone of the interior space during transformation to a second state.

A method of controlling temperature within a multi-zone transport unit using a multi-temperature transport refrigeration system (TRS) is disclosed. The method includes providing a thermal accumulator including a phase change material in a first state in a first of a plurality of zones of the multi-zone transport unit; heating or cooling the first of the plurality of zones of the multi-zone transport unit with the thermal accumulator to a first temperature; and transferring thermal energy from the first of the plurality of zones of the multi-zone transport unit to the thermal accumulator. The method further includes absorbing, by the thermal accumulator, thermal energy as the phase change material changes to a second state and heating or cooling a second of the plurality of zones of the multi-zone transport unit to a second temperature.

Comments:

The following is noted with respect to the embodiments described herein.

The thermal accumulator discussed herein can include a PCM that is adaptable to heat or to cool a storage space (e.g., a cargo compartment) to a temperature suitable for the cargo stored in the storage space. The thermal accumulator can also be used for a defrost operation within the storage space.

Operation of the TRS for a refrigerated transport unit can be independent to various thermal loads that occur due to external conditions external the refrigerated transport unit. That is, the thermal accumulator of the TRS can maintain a desired temperature within the storage space of the refrigerated transport unit regardless of external conditions outside of the refrigerated transport unit.

The PCM used in the thermal accumulator can be any fluid which has a solid-liquid transition point in a rage between about −32° C. and about 0° C. The PCM can be compatible with metals, for example, aluminum. The PCM can store heat in a transition phase using a latent heat (e.g., heat of fusion). The PCM can store heat in a liquid phase. The PCM can have a phase transition temperature that absorbs changes in temperature of the refrigerated transport unit.

The thermal accumulator allows a transfer of heat from the PCM to an air space within the storage space and vice versa. The heat exchanger can include a single, dual, or multiple pass design. The thermal accumulator can use a natural or forced convection to facilitate heat exchange between the PCM and an air space within the storage space. In some embodiments, the thermal accumulator can include a wall or walls with a substantially flat surface and a wall or walls with at least a partially enhanced (e.g., ribbed surface). The thermal accumulator can store a PCM and/or include an empty or free expansion space within the thermal accumulator.

In some embodiments, a thermal accumulator compartment storing a thermal accumulator can be retrofitted into/onto a refrigerated transport unit. The thermal accumulator compartment can be installed to the refrigerated transport unit without specialized equipment. In some embodiments, the thermal accumulator compartment can be designed such that the weight of the thermal accumulator compartment can be supported by a floor, one or more side walls or a ceiling of the refrigerated transport unit. In some embodiments, the PCM can be provided in the thermal accumulator from the top.

The TRS can provide a defrost operation. In some embodiments, a second fluid or refrigerant may be used to perform a defrost operation. In some embodiments, the TRS can include an optional defrost device (e.g., heating bar(s), heating sheet(s), heating tube(s), etc.) for performing the defrost operation. In some embodiments, the thermal accumulator can include a second fluid or refrigerant line to perform the defrost operation. In some embodiments, the defrost operation can be performed in less than 24 hours.

In some embodiments, the TRS can include one or more fans. The power of the fans can be adjusted based on a temperature within the storage space. The fans can provide an air flow rate sufficient to reach a desired amount of heat transfer from the PCM in the thermal accumulator to an air space within the storage space and vice versa. The fans can be controlled/adjusted based on a desired set point temperature within the storage space.

BRIEF DESCRIPTION OF THE DRAWINGS

References are made to the accompanying drawings that form a part of this disclosure and which illustrate embodiments in which the systems and methods described in this specification can be practiced.

FIG. 1 illustrates a transport refrigeration system (TRS) for a refrigerated transport unit, according to some embodiments.

FIG. 2 illustrates a TRS for a refrigerated transport unit, according to other embodiments.

FIG. 3 illustrates a TRS for a refrigerated transport unit, according to other embodiments.

FIG. 4 illustrates a TRS for a refrigerated transport unit, according to other embodiments.

Like reference numbers and designations in the various drawings represent like elements throughout.

DETAILED DESCRIPTION

Embodiments of this disclosure relate generally to a transport refrigeration system (TRS). More specifically, the embodiments relate to a multi-temperature TRS including a thermal accumulator having a phase change material (PCM).

As disclosed herein, a multi-temperature TRS can include a transport refrigeration unit (TRU) which is attached to a transport unit to control the environmental condition (e.g., temperature, humidity, air quality, etc.) of an interior space of the refrigerated transport unit. The TRU can include, without limitation, a compressor, a condenser, an expansion valve, an evaporator, and fans or blowers to control the heat exchange between the air within the interior space and the ambient air outside of the refrigerated transport unit. The multi-temperature TRS can additionally include one or more remote evaporator units and/or one or more thermal accumulators and/or thermal accumulator modules. A thermal accumulator as used herein can include a thermal accumulator module. In such systems, the thermal accumulator may allow the TRU to be disabled for a period of time while still maintaining the desired environmental condition. In some multi-temperature TRSs, the TRU is not required and the environmental condition can be controlled using the thermal accumulator.

A “transport unit” includes, for example, a container on a flat car, an intermodal container, truck, a boxcar, or other similar transport unit.

A “refrigerated transport unit” includes, for example, a transport unit having a TRS that can be used to transport perishable items such as, but not limited to, produce, frozen foods, and meat products.

A “transport refrigeration system” (TRS) includes, for example, a refrigeration system for controlling an environmental condition such as, but not limited to, temperature, humidity, and air quality of a refrigerated transport unit. The TRS may be a vapor-compressor type refrigeration system, a thermal accumulator type system, or any other suitable refrigeration system that can use a heat transfer fluid, cold plate technology, or the like.

A “heat transfer fluid” includes, for example, refrigerant, a cryogenic liquid such as, but not limited to, liquid nitrogen, liquid carbon dioxide, or the like.

A “zone” includes, for example, a portion of an area of an interior space of the refrigerated transport unit.

FIG. 1 illustrates a TRS 100 for a refrigerated transport unit 125, according to some embodiments. The TRS 100 includes a TRU 110 that controls refrigeration within the refrigerated transport unit 125. The TRU 110 is disposed on a front wall 130 of the refrigerated transport unit 125. Examples of refrigerated transport units include, but are not limited to, a truck or trailer unit that can be attached to a tractor, a ship board container, an air cargo container or cabin, an over the road truck cabin, or the like. The TRU 110 includes a programmable TRS Controller 135 that may include a single integrated control unit 140 or that may include a distributed network of TRS control elements (not shown). The number of distributed control elements in a given network can depend upon the particular application of the principles described in this specification.

The refrigerated transport unit 125 includes an interior space 150 that can be divided into a plurality of zones 152 (a front host zone 152 a, a center remote zone 152 b, and a rear remote zone 152 c). In some examples, each of the zones 152 can have a set point temperature that is the same or different from one another, and may be separated by a wall/partition 155.

As shown in FIG. 1, an evaporator portion 160 of the TRU 110 is configured to provide cooling and/or heating/defrosting to the front host zone 152 a. The center remote zone 152 b and the rear remote zone 152 c each includes a remote evaporator unit 165 that is configured to provide cooling and/or heating/defrosting to the center remote zone 152 b and the rear remote zone 152 c, respectively. The remote evaporator units 165 are each fluidly connected to the TRU 110 and are part of a refrigeration circuit (not shown) that allows a heat transfer fluid to pass through the evaporator portion 160 and the remote evaporator units 165. The TRU 110 and each of the remote evaporator units 165 also include a zone temperature sensor 170 configured to measure temperature in the respective zone 152 in which the zone temperature sensor 170 is provided and send the measured zone temperature to the TRS Controller 135. In some embodiments, the zone temperature sensors 170 can be separate from the remote evaporator units. Also, in some embodiments, the zone temperature sensors 170 can be return air temperature sensors that are configured to measure a return air temperature of the remote evaporator units 165. As discussed herein, an “evaporator unit” can refer to an evaporator portion provided in a TRU (e.g., the evaporator portion 160) or a remote evaporator unit (e.g., the remote evaporator unit 165).

While the zones 152 in FIG. 1 are divided into substantially equal areas, it is to be realized that in other embodiments the size of the zones 152 can vary based on user requirements. Also, it is appreciated that the interior space 150 may be divided into any number of zones and in any configuration that is suitable for refrigeration of the different zones.

Generally, the TRS Controller 135 is configured to control a refrigeration cycle of the TRS 100. In one example, the TRS Controller 135 controls the refrigeration cycle of the TRS 100 to obtain various operating conditions (e.g., temperature, humidity, air quality etc.) of the interior space 150 as is generally understood in the art. This can include controlling operation of the refrigeration cycle such that each of the zones 152 reach and maintain the desired set point temperature.

The TRS Controller 135 generally can include a processor (not shown), a memory (not shown), a clock (not shown) and an input/output (I/O) interface (not shown) and can be configured to receive data as input from various components within the TRS 100, and send command signals as output to various components within the TRS 100.

In some embodiments, one or more of the remote evaporator units 165 can be removed and alternatively replaced with one or more thermal accumulators similar to the embodiments described with respect to FIGS. 2-4 below. In such embodiments, the TRU 110 is not required, which can reduce the weight of the refrigerated transport unit 125. In some embodiments, this may improve a fuel efficiency of a vehicle pulling the refrigerated transport unit 125. In other embodiments, the TRU 110 may be included in conjunction with the one or more thermal accumulators or thermal accumulator modules. The TRU 110 is not present in some embodiments. In such embodiments, the refrigeration within the refrigerated transport unit 125 can be controlled using one or more thermal accumulators or thermal accumulator modules. TRSs that include thermal accumulators and thermal accumulator modules are described in further detail in accordance with FIGS. 2-4 below.

FIG. 2 illustrates a TRS 200 for a refrigerated transport unit 205, according to other embodiments. Aspects of FIG. 2 can be the same as or similar to aspects of FIG. 1. The TRS 200 includes a ceiling thermal accumulator 210A and a wall thermal accumulator 210B that control refrigeration within the refrigerated transport unit 205. For simplicity of this specification, the ceiling thermal accumulator 210A and the wall thermal accumulator 210B are referred to hereinafter as the thermal accumulators 210 unless specifically indicated otherwise. In some embodiments, the TRS 200 includes a fan 215 that, with the thermal accumulators 210, can control refrigeration within the refrigerated transport unit 205. The TRS 200 can also optionally include a TRU 110. In some embodiments, the TRS 200 can include one or more additional elements, such as, but not limited to, a programmable TRS controller (e.g., the TRS controller 135 of FIG. 1, not shown in FIG. 2), an evaporator (e.g., the evaporator 160 of FIG. 1, not shown in FIG. 2), one or more remote evaporator units (e.g., the remote evaporator units 165 of FIG. 1, not shown in FIG. 2), or the like.

The thermal accumulators 210 can be interchangeable and capable of being removed from the refrigerated transport unit 205. In some embodiments, the thermal accumulators 210 include a heat exchanger. The thermal accumulators 210 can each represent a single thermal accumulator, a plurality of thermal accumulators, a thermal accumulator module including a plurality of thermal accumulators, or combinations thereof.

The refrigerated transport unit 205 includes an interior space 220 that is divided into a plurality of zones 225 including a first zone 225A and a second zone 225B, separated by a partition 230. In some embodiments, each of the zones 225 can have the same set point temperature. In other embodiments, each of the zones 225 can have a different set point temperature. As illustrated, the zones 225 are divided into substantially equal areas. However, it is appreciated that in other embodiments, the size of each of the zones 225 can be modified based on a user requirement. The interior space 220 can be divided into any number of zones and in any configuration that is suitable for refrigeration of the different zones. The partition 230 includes an aperture 235 where the fan 215 is provided to allow airflow communication between the first zone 225A and the second zone 225B. The first zone 225A is illustrated as including two thermal accumulators 210. The number and placement of the thermal accumulators 210 can vary. Generally, the particular application (e.g., item being transported, set point temperature, etc.) is determinative of the number and configuration of thermal accumulators 210.

The thermal accumulators 210 are configured to control a temperature in the first zone 225A, according to some embodiments. This includes providing cooling to the first zone 225A in some embodiments and providing heating to the first zone 225A in other embodiments. The second zone 225B is configured to receive air from the first zone 225A via the aperture 235 and the fan 215. In particular, the fan 215 can be used to pull air from the first zone 225A into the second zone 225B such that the outflow of the fan 215 is in the direction indicated by the arrow A. The first zone 225A can be maintained at a first set point temperature and air from the first zone 225A can be used to cool the second zone 225B to a second set point temperature. In some embodiments, the first zone 225A can be used to store frozen goods at a first temperature and the second zone 225B can be used to store fresh goods at a second temperature which is greater than the first temperature. It is to be understood that the first zone 225A and the second zone 225B can be interchanged. That is, the thermal accumulators 210 can be disposed in the second zone 225B and the fan 215 can pull air from the second zone 225B into the first zone 225A.

The fan 215 can have a variety of designs so long as it pulls air from the first zone 225A toward the second zone 225B. For example, the fan 215 can be a variable speed fan that is adjusted to modify the environmental conditions of the second zone 225B. In other embodiments, the fan 215 can be a fixed speed fan and include a damper (not shown) that can be opened or closed to control the airflow into the second zone 225B. In some embodiments, the fan 215 can be a variable speed fan and can also include a damper. The speed of the fan 215, whether the fan is enabled, and/or the position of a damper can be controlled by a controller for the TRS (e.g., the TRS controller 135 of FIG. 1).

As discussed above, the TRS 200 can optionally include the TRU 110, according to some embodiments. The TRU 110 can include an evaporator (e.g., the evaporator 160 of FIG. 1, not shown in FIG. 2) and/or one or more remote evaporator units (e.g., the remote evaporator units 165 of FIG. 1, not shown in FIG. 2) that is disposed in the first zone 225A, the second zone 225B, or both the first zone 225A and the second zone 225B. In some embodiments, the TRU 110 does not include an evaporator or a remote evaporator unit disposed in the interior space 220 of the refrigerated transport unit 205. Instead, one or more of the thermal accumulators 210 can include an internal heat exchanger. In such embodiments, piping (not shown) can fluidly connect the TRU 110 with the internal heat exchanger of the one or more of the thermal accumulators 210. Accordingly, the TRU 110 can provide a heat transfer fluid to the one or more thermal accumulators 210 to, for example, charge the phase change material provided in the one or more thermal accumulators.

The TRU 110 can be enabled to cool the thermal accumulators 210 prior to beginning transit and disabled once in transit. In other embodiments, the TRU 110 can be enabled to cool the thermal accumulators 210 prior to transit and then cycle on and off during transit in order to keep the thermal accumulators 210 at about their phase change temperature during transit. In other embodiments, the TRU 110 can be enabled during transit and disabled when not in transit, which can reduce noise, for example, when the refrigerated transport unit 200 is parked.

FIG. 3 illustrates a TRS 300 for a refrigerated transport unit 205, according to other embodiments. Aspects of FIG. 3 can be the same as or similar to aspects of FIGS. 1-2. The TRS 300 includes ceiling thermal accumulators 210A, 210C and wall thermal accumulators 210B, 210D that control refrigeration within the refrigerated transport unit 205 and can optionally include a TRU 110. For simplicity of this specification, the ceiling thermal accumulators 210A, 210C and the wall thermal accumulators 210B, 210D are referred to hereinafter as the thermal accumulators 210 unless specifically indicated otherwise. In some embodiments, the TRS 300 can include one or more additional elements such as, but not limited to, a programmable TRS controller (e.g., the TRS controller 135 of FIG. 1, not shown in FIG. 3), an evaporator (e.g., the evaporator 160 of FIG. 1, not shown in FIG. 3), and/or one or more remote evaporator units (e.g., the remote evaporator unit 165 of FIG. 1, not shown in FIG. 3), or the like.

The thermal accumulators 210A, 210B are configured to control temperature in the first zone 225A and the thermal accumulators 210C, 210D are configured to control temperature in the second zone 225B. In some embodiments, the thermal accumulators 210A, 210B in the first zone 225A can be selected to provide heating or cooling at a first temperature to the first zone 225A while the thermal accumulators 210C, 210D in the second zone 225B can be selected to provide heating or cooling at a second temperature to the second zone 225B. In some embodiments the first and second temperatures can be the same. In other embodiments, the first and second temperatures can be different. The amount of heating or cooling provided by each of the thermal accumulators 210 can be controlled based on, for example, the phase change material provided in the thermal accumulators 210 to provide more heating or cooling by the thermal accumulator in zone 1 than zone 2, or vice versa. The phase change material provided in each the thermal accumulators 210 can accordingly provide control over a set point temperature, and can provide closer control of a temperature variation between different locations in the refrigerated transport unit 205. For example, the ceiling thermal accumulators 210A, 210C and the wall thermal accumulator 210B, 210D can have different phase change materials.

As discussed above, the TRS 300 can include the TRU 110. In such embodiments, the TRU 110 can function similar to the description provided in accordance with FIG. 2 above.

In some embodiments, the TRS 300 can additionally include a fan (e.g., the fan 215 of FIG. 2, not shown in FIG. 3) and an aperture (e.g., the aperture 235 of FIG. 2, not shown in FIG. 3).

FIG. 4 illustrates a TRS 400 for a refrigerated transport unit 205, according to other embodiments. Aspects of FIG. 4 can be the same as or similar to aspects of FIGS. 1-3. The TRS 400 includes a ceiling thermal accumulator 210A and a wall thermal accumulator 210B, a TRU 110, and a remote evaporator unit 165 that controls refrigeration within the refrigerated transport unit 205. For simplicity of this specification, the ceiling thermal accumulator 210A and the wall thermal accumulator 210B are referred to hereinafter as the thermal accumulators 210 unless specifically indicated otherwise. In some embodiments, the TRS 400 can include one or more additional elements such as, but not limited to, a programmable TRS controller (e.g., the TRS controller 135 of FIG. 1, not shown in FIG. 4), an evaporator (e.g., the evaporator 160 of FIG. 1, not shown in FIG. 4), an additional remote evaporator unit (e.g., the remote evaporator unit 165 of FIG. 1, not shown in FIG. 4), or the like.

In this embodiment, the thermal accumulators 210 are configured to provide cooling to the first zone 225A. In other embodiments, the thermal accumulators 210 can be configured to provide heating to the first zone 225A. The remote evaporator unit 165 is configured to provide cooling and/or heating/defrosting to the zone 225B. The TRU 110 and the remote evaporator unit 165 function similar to the description provided in accordance with FIG. 1 above.

In some embodiments, the TRS 400 can additionally include a fan (e.g., the fan 215 of FIG. 2, not shown in FIG. 4) and an aperture (e.g., the aperture 235 of FIG. 2, not shown in FIG. 4). In other embodiments, the TRS 400 can also include thermal accumulators 210 in the second zone 225B. In some embodiments, the TRS 400 can include another evaporator 160 in the first zone 225A.

ASPECTS

It is noted that any of aspects 1-6 can be combined with any of aspects 7-12 and any of aspects 13-16.

Aspect 1. A multi-temperature transport refrigeration system (TRS) for a refrigerated transport unit having an interior space divided into a plurality of zones, comprising:

a thermal accumulator in a first of the plurality of zones, wherein the thermal accumulator includes a phase change material in a first state to absorb thermal energy from the first of the plurality of zones of the interior space during transformation to a second state; and

wherein the first of the plurality of zones is maintained at a first temperature and a second of the plurality of zones is maintained at a second temperature.

Aspect 2. The TRS according to aspect 1, wherein the first temperature and the second temperature are the same. Aspect 3. The TRS according to any of aspects 1-2, further comprising:

a fan configured to draw air from the first of the plurality of zones into a second of the plurality of zones.

Aspect 4. The TRS according to any of aspects 1-3, further comprising:

a transport refrigeration unit;

an evaporator unit disposed in one of the first of the plurality of zones and the second of the plurality of zones; and

a heat transfer fluid circuit connecting the transport refrigeration unit and the evaporator unit, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the evaporator unit.

Aspect 5. The TRS according to any of aspects 1-4, further comprising:

a second thermal accumulator in the second of the plurality of zones, wherein the second thermal accumulator includes a phase change material in a first state to absorb thermal energy from the second of the plurality of zones of the interior space during transformation to a second state.

Aspect 6. The TRS according to any of aspects 1-5, further comprising:

a transport refrigeration unit;

a heat exchanger disposed within the thermal accumulator; and

a heat transfer fluid circuit connecting the transport refrigeration unit and the heat exchanger, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the heat exchanger for charging the phase change material.

Aspect 7. A refrigerated transport unit, comprising:

a transport unit including:

-   -   an interior space and a partition dividing the interior space         into a first and a second zone, the first zone configured to be         maintained at a first set point temperature and the second zone         configured to be maintained at a second set point temperature;

a transport refrigeration system, including:

-   -   a thermal accumulator in the first zone, wherein the thermal         accumulator includes a phase change material in a first state to         absorb thermal energy from the first zone of the interior space         during transformation to a second state; and     -   wherein the first zone is maintained at a first temperature and         the second zone is maintained at a second temperature.         Aspect 8. The refrigerated transport unit according to aspect 7,         wherein the first temperature and the second temperature are the         same.         Aspect 9. The refrigerated transport unit according to any of         aspects 7-8, further comprising: a fan configured to draw air         from the first zone into the second zone.         Aspect 10. The refrigerated transport unit according to any of         aspects 7-9, further comprising:

a transport refrigeration unit;

an evaporator unit disposed in one of the first of the plurality of zones and the second of the plurality of zones; and

a heat transfer fluid circuit connecting the transport refrigeration unit and the evaporator unit, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the evaporator unit.

Aspect 11. The refrigerated transport unit according to any of aspects 7-10, further comprising:

a second thermal accumulator in the second zone, wherein the second thermal accumulator includes a phase change material in a first state to absorb thermal energy from the second zone of the interior space during transformation to a second state.

Aspect 12. The refrigerated transport unit according to any of aspects 7-11, further comprising:

a transport refrigeration unit; and

a heat exchanger disposed within the thermal accumulator;

a heat transfer fluid circuit connecting the transport refrigeration unit and the heat exchanger, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the heat exchanger for charging the phase change material.

Aspect 13. A method of controlling temperature within a multi-zone transport unit using a multi-temperature transport refrigeration system (TRS), comprising:

providing a thermal accumulator including a phase change material in a first state in a first of a plurality of zones of the multi-zone transport unit;

heating or cooling the first of a plurality of zones of the multi-zone transport unit with the thermal accumulator to a first temperature;

transferring thermal energy from the first of the plurality of zones of the multi-zone transport unit to the thermal accumulator;

absorbing, by the thermal accumulator, thermal energy as the phase change material changes to a second state; and

heating or cooling a second of the plurality of zones of the multi-zone transport unit to a second temperature.

Aspect 14. The method according to aspect 13, further comprising:

drawing air from the first of the plurality of zones into the second of the plurality of zones.

Aspect 15. The method according to any of aspects 13-14, further comprising:

providing an evaporator unit for heating or cooling one of the first of the plurality of zones and the second of the plurality of zones.

Aspect 16. The method according to any of aspects 13-15, further comprising:

heating or cooling the second of the plurality of zones with a second thermal accumulator to the second temperature.

The terminology used in this specification is intended to describe particular embodiments and is not intended to be limiting. The terms “a,” “an,” and “the” include the plural forms as well, unless clearly indicated otherwise. The terms “comprises” and/or “comprising,” when used in this specification, indicate the presence of the stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and/or components.

With regard to the preceding description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size, and arrangement of parts without departing from the scope of the present disclosure. The word “embodiment” as used within this specification may, but does not necessarily, refer to the same embodiment. This specification and the embodiments described are exemplary only. Other and further embodiments may be devised without departing from the basic scope thereof, with the true scope and spirit of the disclosure being indicated by the claims that follow. 

What is claimed is:
 1. A multi-temperature transport refrigeration system (TRS) for a refrigerated transport unit having an interior space divided into a plurality of zones, comprising: a thermal accumulator in a first of the plurality of zones, wherein the thermal accumulator includes a phase change material in a first state to absorb thermal energy from the first of the plurality of zones of the interior space during transformation to a second state; and wherein the first of the plurality of zones is maintained at a first temperature and a second of the plurality of zones is maintained at a second temperature.
 2. The TRS according to claim 1, wherein the first temperature and the second temperature are the same.
 3. The TRS according to claim 1, further comprising: a fan configured to draw air from the first of the plurality of zones into a second of the plurality of zones.
 4. The TRS according to claim 1, further comprising: a transport refrigeration unit; an evaporator unit disposed in one of the first of the plurality of zones and the second of the plurality of zones; and a heat transfer fluid circuit connecting the transport refrigeration unit and the evaporator unit, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the evaporator unit.
 5. The TRS according to claim 1, further comprising: a second thermal accumulator in the second of the plurality of zones, wherein the second thermal accumulator includes a phase change material in a first state to absorb thermal energy from the second of the plurality of zones of the interior space during transformation to a second state.
 6. The TRS according to claim 1, further comprising: a transport refrigeration unit; a heat exchanger disposed within the thermal accumulator; and a heat transfer fluid circuit connecting the transport refrigeration unit and the heat exchanger, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the heat exchanger for charging the phase change material.
 7. A refrigerated transport unit, comprising: a transport unit including: an interior space and a partition dividing the interior space into a first and a second zone, the first zone configured to be maintained at a first set point temperature and the second zone configured to be maintained at a second set point temperature; a transport refrigeration system, including: a thermal accumulator in the first zone, wherein the thermal accumulator includes a phase change material in a first state to absorb thermal energy from the first zone of the interior space during transformation to a second state; and wherein the first zone is maintained at a first temperature and the second zone is maintained at a second temperature.
 8. The refrigerated transport unit according to claim 7, wherein the first temperature and the second temperature are the same.
 9. The refrigerated transport unit according to claim 7, further comprising: a fan configured to draw air from the first zone into the second zone.
 10. The refrigerated transport unit according to claim 7, further comprising: a transport refrigeration unit; an evaporator unit disposed in one of the first of the plurality of zones and the second of the plurality of zones; and a heat transfer fluid circuit connecting the transport refrigeration unit and the evaporator unit, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the evaporator unit.
 11. The refrigerated transport unit according to claim 7, further comprising: a second thermal accumulator in the second zone, wherein the second thermal accumulator includes a phase change material in a first state to absorb thermal energy from the second zone of the interior space during transformation to a second state.
 12. The refrigerated transport unit according to claim 7, further comprising: a transport refrigeration unit; and a heat exchanger disposed within the thermal accumulator; a heat transfer fluid circuit connecting the transport refrigeration unit and the heat exchanger, the heat transfer fluid circuit configured to direct a heat transfer fluid from the transport refrigeration unit to the heat exchanger for charging the phase change material.
 13. A method of providing controlling temperature within a multi-zone transport unit using a multi-temperature transport refrigeration system (TRS), comprising: providing a thermal accumulator including a phase change material in a first state in a first of a plurality of zones of the multi-zone transport unit; heating or cooling the first of a plurality of zones of the multi-zone transport unit with the thermal accumulator to a first temperature; transferring thermal energy from the first of the plurality of zones of the multi-zone transport unit to the thermal accumulator; absorbing, by the thermal accumulator, thermal energy as the phase change material changes to a second state; and heating or cooling a second of the plurality of zones of the multi-zone transport unit to a second temperature.
 14. The method according to claim 13, further comprising: drawing air from the first of the plurality of zones into the second of the plurality of zones.
 15. The method according to claim 13, further comprising: providing an evaporator unit for heating or cooling one of the first of the plurality of zones and the second of the plurality of zones.
 16. The method according to claim 13, further comprising: heating or cooling the second of the plurality of zones with a second thermal accumulator to the second temperature. 